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Old 12-01-2009, 12:32 PM
Dennis
Dazzled by the Cosmos.

Dennis is offline
 
Join Date: May 2005
Location: Brisbane
Posts: 11,820
Quote:
Originally Posted by Wavytone View Post
- it assumes a stellar rate only, it makes no provision for lunar or solar rates; most good drive correctors from 30 years ago could do that;
From the authors website:

"If the angular velocity of the RA shaft deviates from the prescribed (sidereal or King Rate) velocity value, it accelerates or delays telescope's driving clock. In this way, a high precision, feedback regulated, real-time rotational speed control has been created. Corrective action happens via autoguider input port of telescope's driver unit if its own."

I thought that the King Rate was the drive rate taking into account atmospheric refraction? However, the author does go on to write:

“if you are hunting just about 25-30 degrees above the horizon (and far from the local meridian) with a 1000-1200mm APO refractor, you will be able to apply around 1 minute exposure time only due to the exponentially increasing refraction rate at low altitudes”.

Maybe he's referring to those higher altitudes at which advanced imagers normally image at?

Cheers

Dennis
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